What Share of a Home’s Electricity Does Solar Cover? Measured Annual Offset in 117 LA Homes
Over a year, the typical Los Angeles-area home’s panels made 96% as much electricity as the household used — an annual solar offset of 96%. 55 of 117 homes made at least as much as they used. So can solar power a whole house? On paper, about half of these homes did. In practice none did: even the homes at 100% or more ran directly on their own solar for under half of their electricity, about 44–46%, and took the rest from the grid at night and in winter.
These are the same 117 homes measured in how much solar a home actually uses and how much electricity solar homes still buy. Here the question is the one installers size systems by: over a whole year, how much of the home’s electricity use did its panels produce? Production comes from each system’s production meter, use from its consumption meter, over the home’s latest 12 complete months.
How much of a year’s use the panels make
117 homes, latest 12 complete months each.
| Annual offset | Homes | LADWP | SCE | With battery | Days sending more than buying | Home use covered directly by own solar |
|---|---|---|---|---|---|---|
| under 50% | 10 | 9 | 1 | 0 | 2% | 21% |
| 50–80% | 28 | 17 | 10 | 5 | 22% | 32% |
| 80–100% | 24 | 10 | 14 | 5 | 44% | 40% |
| 100–130% | 31 | 14 | 17 | 8 | 62% | 44% |
| 130% or more | 24 | 5 | 17 | 4 | 83% | 46% |
| Days and coverage: median home in each band. “Covered directly” includes solar stored in a battery and used later. LADWP and SCE columns include only homes whose utility is known with confidence. | ||||||
https://cali-energy.com/research/solar-offset-measured-los-angeles. Aggregated data are free to use under CC BY 4.0 with a link to this page.The offset sorts the homes cleanly. Under 50%, a home sent more to the grid than it bought on only 2% of days; at 100–130% on 62%, and at 130% or more on 83%. What it does not change much is how much of the house runs on its own solar: that share rose from 21% in the smallest band to about 44–46% and stopped there, because the panels can only serve the hours when the sun is up.
By utility and battery
| Group | Homes | Median offset | Middle half | Homes at 100% or more |
|---|---|---|---|---|
| All homes | 117 | 96% | 74–120% | 55 of 117 |
| No battery | 95 | 95% | 72–117% | 43 of 95 |
| With battery | 22 | 107% | 82–125% | 12 of 22 |
| LADWP area | 55 | 87% | 61–110% | 19 of 55 |
| SCE area | 59 | 106% | 87–146% | 34 of 59 |
LADWP homes ran lower, a median 87%, and SCE homes higher, 106%. The LADWP homes in our fleet use more electricity, a median 38 kWh a day against 30, mostly in the hot San Fernando Valley, and a bigger load takes more roof to match. LADWP’s rules also reward stopping near 100%: a surplus becomes a credit that is never paid out, so production beyond the year’s use is worth nothing. See LADWP net metering.
SCE systems that started after April 15, 2023, when net billing replaced NEM 2.0 for new SCE applications, were sized closer to the home’s use: a median 98% offset among 30 homes without a battery, against 114% among 14 earlier ones. LADWP homes without a battery, whose rules did not change, moved less: 83% against 88%. The groups are small and the start date is only a proxy for the tariff, so this is a hint rather than a finding: under net billing a kilowatt-hour sent to the grid earns far less, which makes oversizing less attractive. See NEM 3.0 export credits explained.
Month by month
Every complete home-month in 2023–2025: 2,968 home-months.
| Month | Production as % of use, median | Middle half |
|---|---|---|
| January | 80% | 59–120% |
| February | 98% | 71–141% |
| March | 126% | 98–166% |
| April | 153% | 117–204% |
| May | 141% | 106–188% |
| June | 126% | 101–186% |
| July | 110% | 85–144% |
| August | 94% | 72–118% |
| September | 87% | 67–116% |
| October | 101% | 75–138% |
| November | 85% | 62–115% |
| December | 66% | 49–101% |
The year is two halves. From March through July the typical home’s panels made more than the house used, up to 153% in April, when the sun is high and little needs cooling. In August and September cooling pushed use past production (94% and 87%); October came out about even (101%), and in winter the short days pulled the offset down again (66% in December). A home at 100% for the year banks the spring surplus and draws it back in late summer and winter; the monthly flows are in how much electricity solar homes still buy.
Can solar power a whole house?
On an annual balance, yes for about half of these homes: 55 of 117 made at least as much as they used. In real time, no: a grid-tied system without a battery cannot run the house after sunset, and even the battery homes we measured bought from the grid on almost every day. The homes at 100–130% covered a median 44% of their use directly; the grid carried the rest in both directions. What it takes to go further is in can solar power a whole house and grid-tied vs off-grid vs hybrid solar.
Methodology
- Homes
- All homes in our Enphase monitoring fleet with a consumption meter and 12 complete consecutive months: 117 homes, 22 with a battery. Data checks are described in the methodology of the self-consumption study.
- Annual offset
- Production from the system’s production meter divided by whole-house use from the consumption meter, both summed over the home’s latest 12 consecutive complete months (mostly October 2025 – September 2026).
- Days sending more than buying
- Share of the home’s clean days in those 12 months when exports exceeded purchases.
- Months
- Every complete home-month in 2023–2025 (2,968 home-months); production ÷ use for each home-month.
- Start date
- The date the system began operating in the monitoring record, used as a proxy for when it was interconnected. Individual tariffs are not known.
- Utility area
- From California Energy Commission utility service-area maps, used only where the match is certain or highly likely.
- Limits
- Not a random sample: these are systems we monitor, weighted toward the San Fernando Valley. An offset reflects both the system and the household, and household use changes from year to year.
Frequently asked questions
What is a solar offset?
The share of a home’s yearly electricity use that its panels produce over the same year. A 100% offset means the panels made as much as the home used, not that the home ran on solar alone.
What offset do LA solar homes actually reach?
In the 117 homes we measured, a median 96%, with the middle half between 74% and 120%. 55 homes reached 100% or more.
Can solar panels power a whole house?
Over a year, about half of the homes we measured made as much electricity as they used. Hour by hour, none ran on solar alone: homes at 100–130% offset still took over half of their electricity from the grid, at night and in winter.
Should I size my system above 100%?
It depends on what the surplus earns. LADWP banks a surplus as a credit that is never paid out, and under SCE’s net billing exported energy earns far less than purchased energy costs. In our data, homes without a battery at 130% or more sent 78% of their production to the grid.
Why does my offset change by month?
Because production and use peak at different times. The typical home’s panels made 153% of its use in April but 94% in August and 66% in December.
More research
Next steps
Sizing a system to your own usage?
Prepared by Cali Energy, October 15, 2026. Figures describe systems in our monitoring fleet and are not a guarantee of what any specific roof will produce; orientation, tilt, shade, equipment and weather change results. Not engineering, financial or utility advice. See our Content Disclaimer.